A Perspective Study of Koumiss Microbiome by Metagenomics Analysis Based on Single-Cell Amplification Technique.

Guoqiang Yao,Qiangchuan Hou,Wenjun Liu,Wenyan Hui,Wenyi Zhang,Tiansong Sun,Jie Yu,Bilige Menghe,Heping Zhang,Lai-Yu Kwok

doi:10.3389/fmicb.2017.00165

Guoqiang Yao, Qiangchuan Hou + Show 8 more

Open Access

https://doi.org/10.3389/fmicb.2017.00165

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Abstract

Koumiss is a traditional fermented dairy product and a good source for isolating novel bacteria with biotechnology potential. In the present study, we applied the single-cell amplification technique in the metagenomics analysis of koumiss. This approach aimed at detecting the low-abundant bacteria in the koumiss. Briefly, each sample was first serially diluted until reaching the level of approximately 100 cells. Then, three diluted bacterial suspensions were randomly picked for further study. By analyzing 30 diluted koumiss suspensions, a total of 24 bacterial species were identified. In addition to the previously reported koumiss-associated species, such as Lactobacillus (L.) helveticus. Lactococcus lactis. L. buchneri, L. kefiranofaciens, and Acetobacter pasteurianus, we successfully detected three low-abundant taxa in the samples, namely L. otakiensis. Streptococcus macedonicus, and Ruminococcus torques. The functional koumiss metagenomes carried putative genes that relate to lactose metabolism and synthesis of typical flavor compounds. Our study would encourage the use of modern metagenomics to discover novel species of bacteria that could be useful in food industries.

Highlights

Koumiss, named chige, chigo, arrag, or airag, in the Mongolian language, is a type of traditional fermented dairy product
To detect the low-abundant bacteria in koumiss, the single-cell amplification technique was used to analyze the metagenomes of the samples
Based on a premise that some rare species will be present in one of the dilutions, multiple displacement amplification of the cells was carried out; and around 5 Gb data were generated for every koumiss bacterial suspension

Summary

Introduction

Named chige, chigo, arrag, or airag, in the Mongolian language, is a type of traditional fermented dairy product. It has been a popular food in Mongolia and Inner Mongolia of China for centuries (Zhang and Zhang, 2011). The earliest record of koumiss production can be traced back to the Han Dynasty (BC202-AD202). This product had attained widespread popularity during the Yuan Dynasty (AD1271-AD1368) (Zhang et al, 2010b). Koumiss does provide rich nutrients, including high contents of essential amino acids and vitamins, but is believed to relieve a wide range of medical conditions and is beneficial for postoperative care (Jagielski, 1877; Thompson, 1879)

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